1. Field of the Invention
The present invention relates to a recording apparatus in which the information on a document is read by beam scanning with a semiconductor laser generating plural beams, and more particularly to such apparatus in which the shading phenomenon is prevented at the beam scanning of the information on the document.
2. Description of the Prior Art
In a laser beam printer, the overlaying of a determined format on the output image can be achieved either electrically or optically. In the electrical method a frame memory corresponding to one page of the output image is provided for storing the format information to be overlaid, and the stored information is released simultaneously with the image signals. In the optical method, a format to be overlaid is prepared as a transparency for optical exposure, which is overlapped with a beam irradiation modulated with image signals. These methods are however defective in that the electrical method requires the expensive frame memory and cumbersome software for entering the necessary information into said frame memory, while the optical method requires a negative transparency for overlay in case the laser beam printer performs so-called negative exposure in which the exposed area turns out black in the output image.